1. Field of the Invention
This invention concerns a tool-holder head for machines using radiant energy beams, especially suitable for plasma beam cutting machines.
As known, the machines using radiant energy beams have more and more growing use in the carrying out of several working processes, such as the engraving process through applying a laser beam on flat surfaces of different material, or the cutting process through applying a plasma beam on plates having a certain thickness, according to determinate shaped profiles.
2. Description of Related Art
The machine tools used in these processes are equipped with turrets or tool-holder heads in which the photonic probes, the cutting torches or the used energy beam sources are supported in a vertical position and they can be translated in parallel to themselves staying at a fixed distance from the flat surface of the workpiece.
As it is for other tool-holder heads having a vertical axis, also in these machines the xe2x80x9ctoolxe2x80x9d can be lift up and lowered according to the working surface through drives included in the head itself, while the horizontal advancements take place through movements of the turret according to xe2x80x9cxxe2x80x9d and xe2x80x9cyxe2x80x9d directions.
So, in these machines, the xe2x80x9ctoolxe2x80x9d is constrained to the tool-holder head in such a way so as to move only according to translations towards the xe2x80x9czxe2x80x9d axis or, towards the head axis.
The energy beam source is rigidly constrained to the respective supporting head and it is controlled to slide only according to the head axis direction, i.e. orthogonally to the working surface, or in a tilted direction when, as in some machines, the head can work in a tilted way according to the vertical position.
The distance of the energy beam source""s lower end from the workpiece surface must have a fixed and a constant value during all the working, especially during workings using plasma beams, where, as known, the necessary power and the energy to the holding of the electric arc on which the beam is based are strictly proportional to the arc""s length.
In this case, to obtain an high efficiency of the carried out working process, the above-said distance must be kept constant with predetermined low values.
Consequently, as it is easy to understand, some problems arise due to the irregularity of the surface, to the kind of the material to be worked, to unexpected objects during the cutting run or to other events which can cause the plasma beam source""s terminal part, commonly called cutting torch, to collide against unexpected obstacles and damage itself, in an irreparable way too.
The main aim of this invention is to propose an innovative tool-holder head, through which it can be possible to nullify the risks of damage of the cutting torch in case of impacts or collisions.
Another aim of the invention is to propose an embodiment that enables the easy use of the energy beam machines, allowing a rapid and effective calibration of the zero rate according to the xe2x80x9czxe2x80x9d axis with no metallic materials too.
A further aim is to propose an embodiment easily suitable to the machine tools currently in use.
These and other aims which will become clear in the following description are achieved through a tool-holder head for machines using radiant energy beams including a vertical sliding saddle to which an energy beam source is constrained through an articulated support that is held through elastic means in the embodiment in which said energy beam source is in the position of normal working and which can furthermore allow said radiant energy source to have, respectively, either tilted positions according to the axis of normal working or translated positions according to said position of normal use, respectively when upwards transversal or axial forces are applied to the lower terminal part of said energy beam source.
The tool-holder head also includes sensors fit for sensing the corresponding movements of said energy beam source according to said normal working position, said sensors are connected to the machine control unit, so as to select, according to the kind of sensed movement, the exact step, such as the interruption of working process, or a simple calibration of the working parameters.
Unlike the tool-holder heads usually used in machines using radiant energy beams, there is a useless rigid connection between the head and the energy beam source, useless because said source, unlike the usual tools used in mechanical workings, during the working process is not subject to any transversal stress according to the advance movement, the tool-holder head of the invention has the new characteristic of allowing to the xe2x80x9ctoolxe2x80x9d to tilt or to translate upwards, according to the corresponding supporting saddle, when any stress is applied to the terminal part of the same, avoiding any damaging due to impacts or collisions.
Furthermore, suitable sensors of the xe2x80x9ctoolxe2x80x9d movements according to the normal working position, allow finding, quickly, anomalous conditions and operating on the control of the machine with the more suitable proceeding.